1. Field of the Invention
The present invention relates to a magnetic recording medium. More particularly, it relates to a magnetic recording medium having both characteristics of excellent electromagnetic transfer characteristics and excellent physical characteristic.
2. Description of the Prior Art
Magnetic recording media prepared by coating a magnetic composition comprising a magnetic powder and a resin binder on a substrate have been mainly used. In view of expansion of the fields for application, magnetic recording media having further superior functions have been required.
The conventional binders used for the purpose are mainly combinations of two components of a resin component and a rubber component such as vinyl chloride-vinylidene chloride type copolymer, vinyl chloride-vinyl acetate type copolymer, acrylonitrile type, cellulose type, urethane type, ester type, ethylene type, epoxy type and phenoxy type resins. The combination of polyurethane and vinyl chloride-vinyl acetate copolymer or the combination of polyurethane and nitrocellulose has been mainly used as the binder. Thus, the two component type binders have not been satisfactory to impart both of satisfactory electromagnetic transfer characteristic and physical characteristic because the optimum ratios of the two components for the electromagnetic transfer characteristic or the physical characteristic are different. Both of satisfactory characteristics have not been disadvantageously attained.